In healthcare settings, tunable lighting systems can save energy and support the well-being of patients, staff, and visitors. By changing spectrum and intensity throughout the course of the day, these systems provide benefits for visual and other biological responses to light. To fully realize these benefits, the Pacific Northwest National Laboratory (PNNL) pursues better understanding of occupant preferences and responses to tunable lighting systems through observational research.
Despite the potential benefits and variety of conditions that tunable lighting systems can provide, research documenting occupant preference in healthcare settings is sparse. Recently, researchers at PNNL and Georgia Institute of Technology’s SimTigrate Design Lab partnered on a study of patient preference for tunable light.
This research builds on an earlier study focused on patient-room lighting from a nurse perspective, with both efforts funded by the Department of Energy and conducted in a full-scale mock-up patient room with a tunable LED lighting system at the SimTigrate Design Lab. The tunable lighting system was donated by Signify and the development of the system stemmed from a Department of Energy-funded R&D project.
This patient study included 34 volunteer participants who performed a series of tasks typical of patients, such as reading or watching a video. Each participant conducted these tasks under 12 lighting conditions in a counterbalanced order that included varying illuminance levels, correlated color temperatures (CCTs), and in a few conditions, red or blue colored wall lighting. The participants rated the comfort, intensity, appropriateness, and naturalness of each lighting condition.
Key findings include:
• Participants showed a strong preference for lighting conditions where light was applied in multiple zones across the room instead of a traditional over-bed configuration.
• Participants reported that conditions with CCTs of 5000K and higher were less comfortable and less natural than conditions with lower CCTs.
• Colored lighting on the footwall of the room received a negative reaction.
• A mixture of warmer and cooler luminaire CCTs in different patient room zones was deemed acceptable.
Advanced lighting technologies allow for much greater flexibility, and this research provides important feedback for lighting specifiers and manufacturers regarding the intensity, color, and distributions of light that patients find agreeable.
Edward Clark, previously with ZGF Architects and now director at CIRCA DIES, is an advocate for high-performance and occupant-centric design solutions. In reviewing this study on the patient perspective, Clark reflected that, “This study demonstrates the importance of not forgetting about the basic lighting design tenets when creating a novel lighting system to support wellness.”
The results highlight the need to incorporate the patients’ perspective in the planning of patient rooms in a healthcare environment.
Click here to check out the study.